Honeywell DT90E room thermostat

[Ronaldo]

I have just bought a Honeywell DT90E room thermostat to replace a faulty Heatmiser DS1. I have a Honeywell ST9400c programmer and Honeywell Mid Position Valve. I have read on several forums that the DT90E should be wired LIVE to A, SWITCHED LIVE to B, C is not used and Neutral wire is not used. I have tested my DT90E with a continuity tester and when I adjust the temperature to match the room temperature (or lower) the meter shows that A is switching to C. Surely this means that the SWITCHED LIVE should be connected to C?

 

[snowhead]

From what you have found A is Switching to C when the stat is satisfied.

Turn the stat up to 30 and it'll have continuity A to B

The Internet is often wrong, the Manufacturers instructions are rarely wrong;

http://www.honeywelluk.com/Documents/Installation-Guide/pdf/1072.pdf

 

[Chalked]

Will switch to B or C depending if you want the stat to operate on temp rise, or fall